Area measuring machine using light beams



Sept. 28, 1948. P. E. NOKES 2,450,054

AREA MEASURING MACHINE USING LIGHT BEAMS Original Filed Aug. 25, 1941 5 Sheets-Sheet l Sept. 28, 1948. P. E. NOKES I ,AREAMEASURING MACHINE USING LIGHT BEAMS 3 Sheets-Sheet 2 /0riginal Filed Aug. 25. 1941 ZZZ Jiwentor P}: iliPENo/(Gs By itorne P. E. NOKES AREA MEASURING MACHINE USING LIGHT BEAMS Sept. 28, 1948.

Original Filed Aug. 25, 1941 3 Sheets-Sheet 3 I Inventor Philifi ENoKes By hi AHomey Patented Sept. 28, 1948 AREA MEASURING MACHINE USING LIGHT BEAMS Philip E. Notes, Beverly, Mala, alaignor to United Shoe Machinery Corporation, Flemington, N. 1., a corporation of New Jersey 1 Original application August 25, 1941, Serial'No.

1944, Serial No. 535,115

2 Claims. 1

This invention relates to area measuring of sheet material and is a division of application Berial No. 408,228, filed August 25, 1941, in my name, now Patent No. 2,354,767. While the invention is illustrated with reference to measurement of the superficial areas of hides and skins, it is to be understood that the invention and various important features thereof may have other applications and uses.

In methods and devices heretofore employed in area measuring operations upon sheet material of irregular contour, involving scanning op erations performed with the aid of a photocell, it has been necessary to integrate the time intervals during which the scanning beam is on the surface to be measured, or oil! it, as the case'may be. It is well known that time intervals are difficult to integrate accurately. Furthermore, they may be interfered with, either inadvertently or intentionally, with disastrous results with respect to correct measurement of the work piece. If, for instance, the work piece be retarded in its movement past the seaming beam, due to error in the work feeding operation, the exposure to the scanning operation will be lengthened and an incorrect indication of measurement be obtained. It is a distinct advantage of my invention that there is no integration of irregular and interrupted time intervals. On the contrary, my invention depends simply upon the counting of reflected light beams having a regularly spaced relation to each other, by which the area of a work piece may be readily calculated. Furthermore, the photocell and its associated electrical circuits will respond to the intermittent impulses furnished by the spaced light beams since they are either present or absent, in the latter case being obscured by the work piece on the work backing member. There is no possibility of falsifying the record by displacing the work piece unless it result from deliberate intention.

From one viewpoint, the invention resides in means for selecting, counting and totalizing such.

light beams.

In one embodiment of the invention a polished reflecting surface may be provided on the work support. The reflecting surface is of such size that when a piece of sheet material to be measured is placed on the surface the sheet material will cover only a portion of the surface.

Divided and this application May 11,

Light reflected or emanating from the uncovered portions of the surface functions as a means.

light beams and concomitantly therewith trans- I mits the results of the scanning operation to a second mirror turning at a speed about a vertical axis to scan the first-mentioned mirror for lightbeams in each row and to transmit such beams to the perforations in the periphery of a rapidly rvolving disk, which disk serves as a shutter to selectdiscrete and regularly spaced, individual light beams, which individual light beams are passed or projected to a photo-electric cell serving as an essential element of an indicating means. By such means, the selected light beams proceed from regularly spaced spots or portions of the work supporting surface and the number of of leather. The disclosed arrangement of mirrors for scanning a work support or work backing member and selecting one or more light beams in each oi a plurality of parallel *lines of sources of such light beams ,in an apparatus for measuring stationary pieces of work has the advantage of keeping the movable parts to a minimum, thereby simplifying the structure and reducing the cost of maintenance.

These and other important characteristics and features of the invention. together with novel combinations of parts, will now be described in detail in the specification and then pointed out more particularly in the appended claims.

In the drawings,

Fig. 1 is a front elevation of an area measuring machine illustrating one embodiment of the invention;

Fig. 2 is a plan view from above of the machine shown in Fig. 1 and particularly of the scanning mechanism;

Fig. 3 is a view in elevation of the parts shown in Fig. 2 looking in the direction of the arrow 111;

Fig. 4 is another side elevationail view looking at the mechanism of Fig. 2 in the direction of the arrow IV; and

Fig. 5 is a detail of a counter mechanism specially applicable to this machine.

- tance above the table is a scanning mechanism If comprising a mirror or other reflector II (Fig.

2) carried by a shaft 20 the axis of which is par-. allel to the surface of the table 0. Preferably the mirror is so mounted that the axis of the shaft is in the reflecting surface of the mirror. As shown. the shaft 20 extends centrally across an opening in the platform I8 so that, as the mirror is rotated, it receives simultaneous beams of light reflected from each of successive straight and parallel strips of the table 8 reflecting surface not covered by the work piece on the table,

be placed at 8.7 feet above the work support, the said mirror may be arranged to turn about its horizontal axis at the rate of approximatel R. P. M., in which case the mirror 22 may be rotated about its axis at the rate of about 2000 R. P. M.

Also secured to the shaft 40 is a cam member 42 (Fig. 4) having a low part 44 for the reception of a roller 40 carried at the lower end of a bell crank lever 48, pivoted at 00 to a bracket extending upwardly from the platform I0. At its upper end the lever 40 has pivoted thereto a link 02 the other end of which is also pivotally attached to a ever arm 04, the lower-end of which r is secured to a shaft 00 to which is secured an arm 00' carrying at its free end a shutter 60 adapted to be positioned between the mirror 22 g and the aperture 28 when no work piece is in each strip being narrow and of a length more than sufficient to traverse the work piece. Mounted on the platform I8 opposite to the transverse median line of the primary mirror I0 is a second mirror 22 rotatable about the vertical axis of a shaft 24, said axis being preferably in the plane of the reflecting surface of the mirror 22. It will be readily understood that light will momentarily be directed toward the full length of a substantially straight strip of the upper surface of table 8 and that an amount of that light (dependent upon the area of sheet. material to be measured that is coextensive with the strip) will be scanned by the mirror 22 one time for each of said strips. Light beams refiected from mirror 22 as a result of the scanning pass through an opening or aperture 20 in a tube 2'! to a photoelectric cell 28 in a housing 28, the photocell being in an electrical circuit which will hereinafter be described in detail. From one viewpoint. the primary mirror I8 may be said to scan the work support 8 for line after line of beams (regularly spaced), while the second mirror scans the primary mirror for localized beams from each line of beams, these localized beams being directed to the photocell through the aperture or tube openin 20.

As heretofore stated. the mirror I8 is mounted on a shaft'20 supported in bearings 20 carried by the platform I8. At one end the shaft 20 has secured thereto a link-32 (Figs. 2, 3 and 4), the other end of which carries a pin upon which is mounted a'roller 34 arranged to follow the cam surface of the relatively large cam member 80, the said roller 84 being yieldingly held in contact with the cam by a spring 38 (Fig. 4). As the cam 30 rotates about the axis of its driving shaft 40 (Fig. 2) the mirror I8 is rocked first in one direction and then in the reverse direction, the rate of rotating movement bein about five per minute whereas the mirror 22 is rotated at about 2000 R. P. M. It will be understood. of course, that the rate of rotary movement of the mirrors I8 and 22 should suit a number of factors, such as the size of the work support or backing member. For instance, a convenient size for the work support 8 in an apparatus specially designed for measuring sheep, kid and calf skins is 5 x 6 feet. If, now, the surface of such work support member be considered as divided into sections measuring 1 6 of a foot in. each direction, and if the axis of the mirror I8 position on the table I. For holding the shutter 00 yieldingly in its operative position (shown in Fig 4) there is provided a spring 82 connected to the upper end of the lever arm 54 and to a member 84 rigidly attached to the platform I6. As heretofore stated, the mirror 22 is mounted on a vertical shaft 24 (Fig. 2). At its upper end the shaft 24 has fixedly secured thereto an oblique gear 10 which is arranged to be constantly in mesh with another oblique gear 12 secured to a shaft 14 mounted at its ends in bearings 10 carried by the platform I8. Adjacent its other end the shaft 14 has secured thereto an oblique gear I8 arranged to be constantly in mesh with an oblique gear 00 secured to one end of a shaft 82 having adjacent its other end a worm gear 84 (Fig. 2) in mesh with a worm on armature shaft 88 of an electric motor 80. The arrangement of the gears is such that the shaft 24 of the mirror 22 is rotated at high speed, preferably at about 2000 R. P. M.

In order that the operator may initiate operation of the scanning mechanism, after a work piece has been placed upon the table 8, there is provided a lever I00 (Fig. 2) pivoted at I02 to one end of a shaft I04 slidable endwise in bearings on the under surface of the platform I6, a spring I00 being provided between one of the bearings and a collar I08 fixed to the shaft I04 to urge said shaft I04 constantly toward the left in Fig. 2 to press a roller IIO on the end of the shaft against the face of the cam member 30, the said roller I I0 being in the path of a surface cam H2 (Figs. 2, 4) conveniently carried by cam member 08. It will be observed that the lever I00 has a slot at I I4 for the reception of a pin I I8 extending upwardly from a lever II8 pivotally mounted at I20 on the under side of the platform I0. The' other end of said lever I I8 is forked at I22 and is provided with rolls receivable in a circular recess I24 in a clutch member I26 pinned to a shaft I20 for sliding movement lengthwise thereof. As shown, shaft I28 is mounted in alinement with the shaft 40 in bearings carried by the platform I0 on the lower surface thereof. When moved to the left in Fig. 2 the clutch member I28 engages a second clutch member I29 fixedly secured to the adjacent end of the shaft 40 which carries cam members 3-0 and 42, as above described. Asclearly shown In Fig. 2, the lever I00 is held by a spring I20 with the recess 1 I4 in said lever I00 engaging the pin I I0 on the lever H8. When the lever I00 is manually moved in the direction of the arrow in Fig. 2 the pin H8 is disengaged from the slot H4, thus freeing the lever H0 and the clutch member I20 for movement by spring I40 which is compressed between a staa tionary collar I 82 and the movable clutch member I28; In this way provision is made for clutching the shaft 88 to a source of power represented by the driven shaft I28 (Figs. 2 and 3). which has secured thereto a worm gear I82 arranged to be constantly in mesh with a worm I88 (Fig. 2) on the shaft 82 constantly driven from the electric motor 88, as above described. When the operator moves the hand lever I88 (Fig. 2) in the direction of the arrow (Fig. 2) the shaft 88 is clutched to the driven shaft I28 in the manner above described. with the result that the mirror I8 is oscillated to eflect a scanning operation of the work support for light beams from uncovered portions of the reflecting surface of table 8 surrounding a work piece thereon to be measured. During the time that the mirror I8 is moving in said scanning operation, the shutter 88 is held by the cam 82 in its inoperative position, i. e., in such position as to permit light beams to enter the photocell 28 from mirror 22. At the end of the rotation of the cam 88 and of the mirror I8 (upon completion of the scanning operation) the shutter 88 is moved to its operative position between the mirror 22 and the photoelectric cell 28 to shut off the light beams and at the same instant the face cam H2 arrives in position to shove the shaft I88 toward the right in Fig. 2, thereby causing disengagement of the clutch member I28 with respect to the clutch member I28 so that the shaft 88 comes to rest. the clutch member I28 .being held in its nonclutching position by engagement of the pin 8 on the lever I I8 in the recess I II of the manually operable lever I88. Hence, at the end of the scanning operation one given piece of work the mirror I8 comes to rest with the shutter 88 in itsoperatlve position. cutting off light from the photocell 28. Obviously the purpose is to prevent access of adventitious light impulses to the photocell after measurement of the work piece has been accomplished.

During scanning of the work table 8 by the mirror I8 it will reflect beams parallel to each other and, in the illustrated construction, parallel also to the surface of the work support 8. Since the mirror 22 is turning at high speed it scans the beams being reflected from the mirror surface I8 along a line extending lengthwise of the latter's axis, it being clear that a beam re flected from one end of the mirror I8 will strike the mirror 22 at one angle and that a beam being reflected from a point nearer to the transverse central line of said mirror I8 will strike mirror 22 at a different angle. The mirror 22 scans .the whole length of any given line of beams showing In proper position on the mirror I8 in one rotationof said mirror 22 as the latter views said line of beams from one end to the other while said mirror I8 continues its scanning movement. Since the mirror I8 scans the whole surface of the table in about A of a second the vertical mirror must turn at high speed to scan each line of beams appearing on the primary mirror I8. During the scanning movement of the mirror I8 it will happen that beams will be reflected uniformly from the reflecting surface of the table 8 instead of from a single strip. However, in the construction shown, only thosebeams reach the mirror 22 which are reflected from the mirror I8 along a horizontal path from the latter. This insures that beams from the reflecting surface of table 8 will be reflected by the mirror I8 to mirror 22 in strip after strip and not simultaneously 8 from two or more strips extending substantially parallel to the axis of the mirror. Since the light beams are continuously reflected from mirror 22 toward the aperture 28 and the photocell 28, except when intercepted by the work piece at the first points of light reflection, it is necessary to select certain light beams projected from such first points (where the polished surface of the table 8'is not covered by a work piece I88). the said selected beams comprising beams from cer tain lines or series of light beams which are evenly or regularly spaced. In the illustrated construction. the selecting means is in the form of a perforated shutter or light-chopper I88 positioned to be driven by a horizontal shaft I82, the shutter being located between the vertical mirror 22 and the photocell 28. In an apparatus of the dimensions specified above, this shutter I88 will have about 200 perforations I88 (Fig. 4) located in a circle concentric with the shaft I82 and will rotate at about 9000 R. P. M. As already stated,

there is provided, between the shutter I88 and the photocell 28, a diaphragm with an aperture 28 therein, as in Fig. 2, so located and the aperture being of such size as to direct beams of light passed by the light-chopper I88 to said photocell. The reflection from a highly polished mirror-like surface is so'much more intense than that from any leather surface. even from a smooth white leather surface, that there is no difficulty in providing photocells and circuits which will respond only to the impulses from the polished metal surface. mounted in brackets I18 on the platform I8 and driven by oblique gears I12 and I" from the shaft 82. With such an arrangement, the beams reflected or not reflected from regularly spaced spots on the polished surface of the table 8 may be counted'and the summation of the number of such beams may serve as an indication of the area of the work piece I88.

It will be understood that several scanning devices, including mirror I8 and mirror 22, will be provided in sets and properly combined to take care of large size skins. For instance, in the case of very large areas. such as sides for upper leather. a scanning set will be provided above the center portion of each quarter of the work supporting table 8. the arrangement being such that each photocell in turn sends its-impulses into the counting mechanism hereinafter described.

By reason of the speed of the operation of the scanning device the impulses are received from the photocell very rapidly and they are not sufficiently powerful to operate a mechanical counter. Accordingly, these impulses are delivered through an electronic counting circuitto the operating eiectromagnet of the mechanical counter. A special electronic counting circuit for this purpose is described in my copending application Serial No. 408,229, filed August 25, 1941, for Improvements in electrical counters, now Patent No. 2,354,768. and involves the use of amplifying circults and accumulating condensers to which unit charges are delivered by a trigger or charging.

disclosed the light impulses received by the photocell 28 depend upon the absence. at a Shaft I82 is suitably cessive digits.

particular point, of an article to be measured. Hence it is necessary to subtract the count which has been made from a constant corresponding to the area of the work supporting surface ofthe machine, only a portion of which is covered by the article to be measured. In the illustrated machine, an impulse may be received bythe photocell from each of 3000 squares each onetenth of a foot square. Hence, the constant from which subtraction must be made is 3000.

In Fig. the figure wheels I200 are numbered backwards and are provided with a special correcting device to be described. Inasmuch as the constant is more than one thousand. it will be necessary to provide a counting circuit with an accumulating condenser having a capacity such that it will not be discharged automatically until 101000 unit charges have been received. This circuit will be connected directly to the operating electromagnet I260 of a counter H in association with counters E', F. and G. In each of the counters F, G and H the frames I400 are pivotally mounted at I402 upon a base I800 in which there is provided a correctingcoil I302 of an electromagnet and the action of this coil issimilar to the mechanical carry-over utilized in mechanically interconnected counters. When the coil I002 is energized it draws down a latch I004 engaging a projection I000 and allows the whole frame I400 to be drawn down by a spring 8008, thereby tilting the frame I400 until the proJection I000 strikes a stop pin IOI0. This angular tilting movement of the frame I400 is sumcient to carry the next number on the figure wheel I250 (rotatable about the axis of pivot I402) to a position opposite the reference pointer IZ'BI, thus in effect subtracting 1 from the digit to be read on the figure wheel and corresponding in effect to a movement of the reference pointer I25I a distance equal to the space between suc- It will be observed that a return spring I252 is provided on each of the counters E, F and G and that they are arranged to return these figure wheels to zero after the count has been taken. On the other hand, the corresponding spring I252 on the counter H is arranged to return its figure wheel to the'number 3, for the reason that the impulses received are to be subtracted from the constant 3000. In the counter G there has been provided both the correcting coil I302. and a coacting and additional coil I3I2. In the counter H, three correcting coils I302, I3I2 and I322 are positioned on the same core and an impulse received by any one of the three is sufficient to release the latch I304 and to permit the tilting of the corresponding frame I400 to bring I which is to be subtracted from the constant 3000 may vary from 1 to 2999 and the arrangement is such that, when any of the digits in that counted figure which is to be subtracted is a finite number other than zero, then all the digits to be read at the left of it must be corrected by subtracting 1. As shown, the counters E, F, G and H are arranged one above the other so that the operating magnets I280 may obviously be connected to similar individual discharge circuits (not shown).' The final result to be read from the figure wheels will be read from the figure wheels in the counters H, G, F, E from bottom to top.

In accordance with this principle, the coils I002 in the counters F, G and H are connected to the circuit which energizes the electromagnet I200 of the counter E so-that a correction of one will be made whenever the number recorded by counter E is one or more than one. Similarly, the coils III2 (of counters G and H) are connected to the circuit which energizes the magnet I200 of the counter F, and the remaining coil I022 in the counter H is connected to the energizing circuit of a magnet I200 in the counter G. When no impulses are received in any of the counters E, I" and G, the corresponding correcting coils I002, I3I2 and I222 will not be energlzed.'

On the other hand, the action of these coils is additive so that the energization of any one of them is sufficient to release the latch I004 of the counters below it which will correspond to the figures to the left of this digit in the final result.

It will be understood that the counting or accumulating and carrying over usually performed mechanically are here done electrically, requiring only the final setting of a group of independent figure wheels I200 to be done mechanically.

Having described my invention. what I claim a new and desire to secure by Letters Patent of the United States is:

1. An apparatus for measuring the area of sheet material including a work supporting memher having a reflecting surface for light received from a source spaced therefrom, a mirror system for scanning the said reflecting surface to transfer light reflected from said surface in the form of a beam, a photocell Positioned in the path of the said beam, a shutter mounted to operate in synchronism with the mirror scanning system and regularly to interrupt passage of the beam to the photocell, and means associated with said photocell for counting the impulses produced therein as an indication of the area of sheet material placed upon said supporting member.

2. An apparatus for measuring the area of sheet material including a work supporting member having a reflecting surface for light received from a source spaced therefrom, a mirror mounted for scanning the work supporting member to transfer light reflected from said surface in the form of a beam, a second mirror rotated on an axis at an angle to the first mirror to reflect light received from the first mirror, a photocell positioned in the path of the light reiiected from the second mirror, a shutter mounted to' operate in synchronism with the two mirrors regularly to interrupt passage of light to the photocell, and means associated with said photocell for counting the impulses produced therein as an indication of the area of sheetmaterial placed upon said supporting member.

PHILIP E. NOKES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,184,156 Bowles Dec. 19, 1939 2,184,159 Stockbarger et a1. Dec. 19, 1939 2,184,162 Stockbarger et al. Dec. 19, 1939 

